A Triple-Mode Flexible E-Skin Sensor Interface for Multi-Purpose Wearable Applications

This study presents a flexible wireless electronic skin (e-skin) sensor system that includes a multi-functional sensor device, a triple-mode reconfigurable readout integrated circuit (ROIC), and a mobile monitoring interface. The e-skin device's multi-functionality is achieved by an interlocked micro-dome array structure that uses a polyvinylidene fluoride and reduced graphene oxide (PVDF/RGO) composite material that is inspired by the structure and functions of the human fingertip. For multi-functional implementation, the proposed triple-mode ROIC is reconfigured to support piezoelectric, piezoresistance, and pyroelectric interfaces through single-type e-skin sensor devices. A flexible system prototype was developed and experimentally verified to provide various wireless wearable sensing functions-including pulse wave, voice, chewing/swallowing, breathing, knee movements, and temperature-while their real-time sensed data are displayed on a smartphone

A Stepwise Split Power-Driving Scheme With Automatic Slope Control for EMC-Enhanced LIN Transceiver

This paper proposes a split power-driving scheme for electromagnetic interference robust design and its automatic stepwise digital slope control for suppression of spectral emission. This analog-digital hybrid method gives power saving effect up to 24.4%, and also production reliability can be improved by utilizing a failure detection and recovery scheme. For feasibility of the proposed electromagnetic compatibility (EMC) scheme, a Local Interconnect Network transceiver prototype is fabricated in a 0.18-??m BCD process, and experimentally verified to provide EMC-enhanced operation with low-cost and low-power overheads

High-Valent Iron Redox-Mediated Photoelectrochemical Water Oxidation

© 2021 American Chemical SocietyFe3+ is widely used as a conduction band electron acceptor in the photocatalytic and photoelectrochemical (PEC) oxidation of water and various substrates. However, a question of the possible involvement of Fe3+ as a valence band hole acceptor has been raised. Herein, we demonstrate that the PEC water oxidation using oxide semiconductor (WO3, TiO2, and BiVO4; primarily WO3) films can proceed via the formation of high-valent iron species in the presence of aqueous Fe3+ ions at pH 1–3. The presence of Fe3+ (1–100 mM) enhances the photocurrent generation, O2 evolution, and the Faradaic efficiency (FE) of ∼90% with a biased WO3 electrode (1.23–1.88 VRHE), whereas the formation of Fe2+ is significantly inhibited. An in situ transient absorption spectroscopic analysis reveals the formation of high-valent iron species. The selective oxidation of dimethyl sulfoxide to dimethyl sulfone using in situ high-valent iron species is achieved with an FE of ∼98% in the PEC reaction with Fe3+. The proposed reaction mechanism should call for attention to the conventional role of Fe3+ in the PEC reaction.11Nsciescopu

Constraining the First Year of Ice-Free Arctic: Importance of Regional Perspective

The ice-free Arctic in summer not only symbolizes human-induced climate change but also highlights the need to critically consider climate change adaptation policies. To constrain projections when the Arctic Ocean will first become ice-free, studies have typically combined the historical observations of the Arctic sea ice area (SIA) with future emission scenario simulations. However, these studies primarily relied on the historical climatology and trend of the Arctic SIA, without considering regional variations. In this study, we analyze September SIA projections using the Coupled Model Intercomparison Project Phase 6 (CMIP6) model simulations, while considering Arctic sub-regions. Additionally, we assess the impact of incorporating sub-region September SIA when constraining the first year of ice-free Arctic in September. CMIP6 models generally overestimate the historical September SIA decreasing trend in the central Arctic, whereas they underestimate this trend in the surrounding shelf seas. The central Arctic, where the region expected to retain sea ice for the longest period in the future, holds particular significance for projecting when the Arctic will first become ice-free. Consequently, when we employ the historical trend of September SIA in the central Arctic as a constraint, observationally-constrained projections suggest a delay of 12 years (2056) for the first ice-free September compared to raw/unconstrained projections (2044 in model average) under a high-emission scenario. These findings underscore the importance of considering model biases in central Arctic SIA when constraining projections of the first year of ice-free Arctic, which may occur later than previously projected in many studies.Y

Attributing Causes of 2015 Record Minimum Sea-Ice Extent in the Sea of Okhotsk

In 2015, the sea ice extent (SIE) over the Sea of Okhotsk (Okhotsk SIE) hit a record low since 1979 during February-March, the period when the sea ice extent generally reaches its annual maximum. To quantify the role of anthropogenic influences on the changes observed in Okhotsk SIE, this study employed a fraction of attributable risk (FAR) analysis to compare the probability of occurrence of extreme Okhotsk SIE events and long-term SIE trends using phase 5 of the Coupled Model Intercomparison Project (CMIP5) multimodel simulations performed with and without anthropogenic forcing. It was found that because of anthropogenic influence, both the probability of extreme low Okhotsk SIEs that exceed the 2015 event and the observed long-term trends during 1979-2015 have increased by more than 4 times (FAR = 0.76 to 1). In addition, it is suggested that a strong negative phase of the North Pacific Oscillation (NPO) during midwinter (January-February) 2015 also contributed to the 2015 extreme SIE event. An analysis based on multiple linear regression was conducted to quantify relative contributions of the external forcing (anthropogenic plus natural) and the NPO (internal variability) to the observed SIE changes. About 56.0% and 24.7% of the 2015 SIE anomaly was estimated to be attributable to the external forcing and the strong negative NPO influence, respectively. The external forcing was also found to explain about 86.1% of the observed long-term SIE trend. Further, projections from the CMIP5 models indicate that a sea ice-free condition may occur in the Sea of Okhotsk by the late twenty-first century in some models. 키워드112sciescopu

Understanding climate changes in East Asia and Europe based on spatial climate analogs

Spatial climate analogs effectively illustrate how a location’s climate may become more similar to that of other locations from the historical period to future projections. Also, novel climates (emerging climate conditions significantly different from the past) have been analyzed as they may result in significant and unprecedented ecological and socioeconomic impacts. This study analyzes historical to future spatial climate analogs across East Asia and Europe, in the context of climatic impacts on ecology and human health, respectively. Firstly, the results of climate analogs analysis for ecological impacts indicate that major cities in East Asia and Europe have generally experienced novel climates and climate shifts originating from southern/warmer regions from the early 20th century to the current period, primarily attributed to extensive warming. In future projections, individual cities are not expected to experience additional significant climate change under a 1.5 °C global warming (warming relative to pre-industrial period), compared to the contemporary climate. In contrast, robust local climate change and climate shifts from southern/warmer regions are expected at 2.0 °C and 3.0 °C global warming levels. Specially, under the 3.0 °C global warming, unprecedented (newly emerging) climate analogs are expected to appear in a few major cities. The climate analog of future projections partially align with growing season length projections, demonstrating important implications on ecosystems. Human health-relevant climate analogs exhibit qualitatively similar results from the historical period to future projections, suggesting an increasing risk of climate-driven impacts on human health. However, distinctions emerge in the specifics of the climate analogs analysis results concerning ecology and human health, emphasizing the importance of considering appropriate climate variables corresponding to the impacts of climate change. Our results of climate analogs present extensive information of climate change signals and spatiotemporal trajectories, which provide important indicators for developing appropriate adaptaion plans as the planet warms

Hysteresis and irreversibility of global extreme precipitation to anthropogenic CO2 emission

Understanding of extreme precipitation change in response to CO2 forcing and associated socioeconomic exposure is limited. In this study, a comprehensive analysis is conducted to explore the response of global extreme precipitation to CO2 forcing in terms of hysteresis and reversibility effect and associated population exposure. In this regard, climate outputs under two idealized CO2 scenarios such as ramp-up (RU; about +1% annually until quadrupling of present level) and ramp-down (RD; around −1% annually set back to present level) from Community Earth System Model version 1.2, and the projected population data from the five shared Socioeconomic Pathways (SSPs) are used. Extreme precipitation events are evaluated using the number of heavy precipitation days (R30 mm), maximum consecutive 5-day precipitation (Rx5day), and the precipitation of very wet days (R95pTOT) indices. Results show that the magnitude of extreme precipitation change and associated population exposure is higher in the CO2 reduction period (RD) than in RU. All the indices show substantial irreversible and hysteresis effects, ∼69% of the global land is expected to experience irreversible changes in extreme precipitation. Further, the hotspots of irreversibility (the region with irreversible change and a large hysteresis) will emerge in >20% of the global area. Spatially, strong hysteresis and irreversibility are particularly concentrated over global land monsoon regions. The leading exposure is estimated under SSP3 combined with both RU and RD periods. Under the SSP3-RD combination, the highest population exposure is estimated at ∼67.1% (globally averaged), and ∼72% (averaged over hotspots) higher than that of the present day. The exposed population is prominent in South Africa and Asia. Notably, the population change effect is the principal factor in global exposure change, while it is the climate change effect over the hotspots of irreversibility. These findings provide new insight into policymaking that only CO2 mitigation effort is not enough to cope with extreme precipitation, rather advanced adaptation planning is a must to have more socio-economic benefits